Cativyl alcohol and method of preparing it



Patented Mar. 19, 1940 r'rsu'r orr cr.

CATIVYL ALCOH'OL AND METHOD OF PREPARING IT Nicholas L. Kalman,Cambridge, Mass, assignor to Arthur D. Little,

Incorporated, Cambridg Mass, a corporation of Massachusetts No Drawing.Original application October 15,

1936, Serial No. 105,6

97. Divided and this application June 11, 1937, Serial No. 147,735

Claims.

This invention relates to a new organic alcohol, and to methods ofpreparing it.

This application is a division of my co-pending application, Serial No.105,697, filed October 15, 5 1936, now U. S. Patent No. 2,152,743.

The raw material used as a source of the new organic alcohol and relatedcompounds described herein is the exudate from the species of the treecalled Prioria copaz'fera, Gris, which tree is found abundantly in partsof tropical and semi-tropical countries-for example, along the Caribbeancoast of Panama and Costa Rica. The exudate is properly called Cativoresin, although it is also commonly called Cativa (or Cateva or Catteva)balsam, and also by various local names. The natural exudate is usuallya greenish brown, very tacky and viscous, opaque liquid, and hasespecially when heated, an unpleasant odor. Attempts to use itcommercially have heretofore been without success.

I have found that about 70 to 80% of this resin exudate is in the formof an organic acid. This acid is not readily secured by ordinary methodsof procedure without considerable contamination with other ingredients,and with byproducts which result from the methods of treating. To thisacid, which I have succeeded in obtaining in pure state for the firsttime, I have given the name Cativic acid.

Cativoresin contains as a rule about A; water, 0.1% ash, up to 2%volatile oil, and about of an unidentified acid whichhas a very muchlower boiling point than cativic acid. The two major constituentsofCativo resin are cativic 70 to 80% of the resin, and another substancewhich makes up about 15 to 25% of the resin. This latter substance Ihave found to be an ester of cativic acid with its correspondingalcohol, and have accordingly named it Cativyl cativate. The saidcorresponding alcohol I have prepared for the first time and have givenit the name Cativyl alcohol.

In order that this invention may be fully understood, I will describecativic acid and methods of making it, as well as cativyl alcohol andmethods for its preparation. Furthermore, the processes for producingcativic acid yield cativyl alcohol, or 0 cativyl catlvate, which lattermay then be used for preparing, cativyl alcohol; hence are properly setforth in sufficient detail herein. The aspects of preparing cativicacid, and cativic acid itself, are claimed in the co-pendingapplication, Serial No. 105,697, already referred to.

acid, as mentioned above, which makes up about Cativic acid is a veryviscous and tacky substance; it is a semi-solid having a cold flow, andis colorless or substantiallyso, and nearly entirely odorless. Allattempts at crystallization of this material have so far failed, and asin the case of similar high molecular weight non-crystallizedandoxidizable organic acids, it is a very difficult matter to establisha precise chemical formula and absolute physical and chemicalcharacteristics. It appears, however, to be a definite chemicalcompound, which may exist in one form or as a mixture of isomeric formsall having the same molecular formula, set forth below; Closely relatedcompounds (having, for example, 2 carbon atoms more,-or less) may bepresent in traces; these would be practically impossible to isolate andidentify. This chemical compound, which may or may not be present inisomeric form, I refer to as cativic acid. A series of combustionsonsamples of purified cativicacid give amean of carbon 78.41%, andhydrogen 11.06%. This corresponds to a molecular formula of CzoHsrOz. Itwill be readily apparent that the exact molecular formula of a substancehaving such a high molecular weight is not easy to de- 'termine. Hencethis formula is advanced as being the most probable as far as I havebeen able to ascertain. The mean acid number is found to be 133.8.Cativic acid has an unsaturated bond, but the iodine numberdeterminations according to Wijs method yield varying data according tothe amount of sample taken, time of reaction, etc. Representativesamples of purified cativic acid show an average refractive index of1.509 at 24 CI; a specific gravity of 0.9987 at 23 0.; a viscosity, cc.pipette at 22 C., of 78.5 hours; water under-same conditions, 11.6seconds.

Cativic acid exhibits the properties of a monobasicacid, readily formingsalts. It also readily forms esters, differing from abietic and otherresin acids which esterify only with dlfliculty. Its composition inconjunction with the degree of unsaturation clearly differentiates itfrom the aliphatic acids. With a body of as high molecularmagnitude ascativic acid, a small variation in percentage composition of hydrogen,oxygen, and carbon produces a correspondingly greater apparent variationin composition, but from my researches, there is no compound of thiscomposition or closely approaching the same which has thecharacteristics indicated above and the ability of ready esterification.

Cativic acid is insoluble in water, but soluble in all the commonorganic solvents including'generally aliphatic or aromatic hydrocarbons,alcoso hols, ketones, esters, ethers, chlorinated solvents, etc.

Among the methods which I have used for obtaining cativic acid I willdescribe a distillation process, various types of neutralizationprocesses, and a solvent process. While I will describe each process inconsiderable detail, in order that they may be readily followed andcarried out, it should be definitely understood that many modificationsare possible, and the invention is limited only by the scope of theappended claims.

In carrying out the distillation process, I may first filter the Cativoresin (which is advantageously warmed or dissolved in a suitablesolvent, to improve its flow) in order to remove dirt and other foreignmatter. This step, however, is not necessary. Then I subject it to heatand preferably to a slight vacuum, equal, say, to a pressure of 200 mm.of mercury, thereby driving 01'? water and other low-boilingconstituents. The pressure during this step may vary considerably. Theremaining constituents,cativic acid and cativyl cativate-do not distillwhile the temperature is below about 200 0., even at a low absolutepressure. (Pressures, in this specification, are given in millimeters ofmercury, and are absolute pressures.) The receiver is now changed, andon raising the temperature to above 200 C., with a low pressure (below10 mm. preferably), cativic acid is distilled ofi, leaving cativylcativate as the residue. Care should be taken, during the distillation,to keep the pressure low; with higher pressures (e. g. 10 mm. or over)there is a tendency for cativic acid to lose CO2, forming thecorresponding hydrocarbon which I call Cativene. (Cativene is asubstantially colorless, thin liquid, boiling at about 160 C. at 3 mm.It is readily obtained by distilling cativic acid-containing material ata temperature and pressure such that cativene is produced by thebreakdown of cativic acid, the pressure being too high (or, in otherwords, the vacuum being too low), and simultaneously, the temperaturebeing too low, to distill off cativic acid itself,--for example, apressure of mm. at about 200 C. is suitable. Cativene appears to havethe molecular formula of cativic acid minus CO2, and also perhaps minustwo atoms of hydrogen). However, once the distillation of cativic acidwell under way, at the indicated low pressure, there is little or nofurther trouble from cativene formation, and any oativene which cameover early in the distillation may be separated by simultaneous orsubsequent fractional distillation or by neutralization of the cativicacid, or by other suitable means. As cativyl cativate does not distillor decompose under the conditions mentioned above, there is a sharpbreak in the distillation when cativic acid has been distilled over, thecativyl cativate remaining behind as a residue. When separating byneutralization, an alkali such as caustic soda together with a suitablesolvent such as water is used, and the cativic acid separated from theother materials including cativene, in the same general way as outlinedbelow under the neutralization process. There is also some tendency forcativic acid and its derivatives to oxidize especially at elevatedtemperatures where progressive discoloration also takes place. This canbe avoided by distilling in the absence of oxygen,e. g. in an atmosphereof nitrogen or carbon dioxide, etc. The cativyl cativate left behind asa residue may then be worked up by procedures hereinafter described forthe production of cativyl alcohol.

In carrying out the neutralization processes, I treat Cativo resin, orother material from which cativic acid is to be removed, with a suitablecompound of a metal or of ammonia, or with an organic base or alcoholforexample, with sodium oxide or hydroxide, ammonium hydroxide, or variousmetallic oxides, carbonates, acetates, or other salts thereof-in otherwords, an organic or inorganic compound having a basic reactionwherebyto form the metal salt or organic base salt, or an ester of cativic acid(metaP here includes ammonium). The salt (or ester) is then treated torecover cativic acid therefrom. There are two aspects to theneutralization treatment, one, where the cativic acid alone, is reactedwith the basic compound, and the other, where also the cativyl cativate,when present, is saponified by an excess of the basic compound over thatrequired to react with the cativic acid alone. cativate reacts to formtwo products,-salt (or ester) of cativic acid with the base (or theadded alcohol), and cativyl alcohol. Hence, when saponification ofcativyl cativate accompanies neutralization of cativic acid, cativylalcohol is a lay-product in the manufacture of cativic acid. or course,procedures of partial saponification, intermediate the two aspects ofthe neutralization treatment just described, may be practiced. Theseneutralization processes therefore commonly result in the production ofcativyl alcohol directly, or of cativyl cativate, which latter may thenbe used in the preparation of cativyl alcohol, as will be describedlater herein.

The various neutralization processes, which or may not includesaponification as set forth above, may be conveniently classified asfollows: I

(1) Recovery of cativic acid from its watersoluble salts in solution.

(2) Recovery of cativic acid from its watersoluble salts after dryingthe latter.

(3) Recovery of cativic acid from its dry am monium salt.

(4) Recovery of cativic acid from its watersoluble salts separated fromacetone solution.

(5) Recovery of cativic acid by the use of relatively high-boilingorganic solvents.

(6) Recovery of cativic acid by first preparing esters thereof (as bythe procedure disclosed in my co-pending application, Serial No. 33,661,filed July 29, 1935, now U. S. Patent No. 2,152,-

741) and subsequently decomposing the resulting esters, as byhydrolysis. The necessary procedure for this will be clear from thedisclosure herein and in S. N. 33,661, and need not be furtherdiscussed.

Taking these up now in order, I will describe each one in detail.

By the first of the above-numbered neutralization processes forobtaining cativic acid I may proceed to obtain all the cativic acidcontained in Cativo resin or other starting material, whether present assuch, or combined with cativyl alcohol as cativyl cativate. A simpleprocedure is to heat or boil the Cativo resin with an aqueous (oralcoholic, or aqueous-alcoholic) caustic solution, whereby the cativylcativate is easily saponified. Alternatively, no heat may be applied,less alkali may be used, and correspondingly less, or no, cativylcativate saponified. All of the resin, except for a small amount of dirtand like impurities, which are readily removed by filtration, is now insolution. Dilution, at least to a considerable degree, of this solutionwith In this latter aspect, cativyl water is possible, without apparentprecipitation-the cativyl alcohol being-undoubtedly held by the soapsolution. To separate these ingredients, the soap solution is shaken outwith a solvent immiscible with water or the alkali cativate. Petroleumether or ethyl ether may be used as such a solvent. The cativyl alcoholis thus dissolved out in the solvent phase, and may be re-- covered asdesired. The alkali cativate, contained in the other phase, maybedecomposed (hydrolyzed) in well-known manner by addition of acomparatively strong acid, whereby cativic acid is produced. Catavicacid may then be readily separated from the other materials, which existas a water solution of alkali salt, alcohol (if any has been used), andany excess of the strong acid,-since cativic acid is insoluble thereinat the relatively high water-content then existing in said solution.

In carrying out the second of the above-numbered neutralizationprocesses, I take Cativo resin,or other substance containing cativicacid,with or without cativyl cativate, and neutralize (or saponify moreor less, as desired) with aqueous, or alcoholic, or aqueous-alcoholicalkali solu tion,-or with solid alkali,-in the presence or absence ofinert material, and then evaporate to dryness. The dry material is thenextracted with a solvent, such as acetone, which extracts the impurities(cativyl cativate, cativyl alcohol, cativene, ethereal oil, etc.) buthas no effect, or substantially none, on the alkali salt of cativicacid. The thus-purified salt of cativic acid is then decomposed, as byhydrolysis with a strong acid, and the cativic acid thus recoveredtherefrom. This salt will, when Cativo is used as the raw material,necessarily contain the salt of the other acid present to the extent ofabout of 1% in natural Cativo. This acid may be removed, prior to theabove treatment, by fractional distillation as already described, or byheating the mixture of this acid and cativic acid (after the hydrolysisstep) to about C. at 7 mm., preferably in a non-oxidizing atmosphere,the impurities distilling over and leaving the pure cativic acid behind.y

The third neutralization process listed above is conveniently carriedout by dissolving Cativo resin, or other cativic acid-containingmaterial, in say three times its weight of petroleum ether, filtering ifdesired, and then leading anhydrous ammonia into the solution. Thisprocedure may be simply neutralization, or neutralization withsaponification of any cativyl cativate present. The ammonium salt ofcativic acid precipitates out as a gummy solid, and the supernatantpetroleum ether, containing the other constituents and by-products, isreadily removed as by decantation. The resulting ammonium cativate maybe purified as desired by washing with petroleum ether. If it isnecessary to further purify the ammonium cativate, for itself or as asource of cativic acid, it may be decomposed (hydrolyzed) by a strongacid, such as hydrochloric or sulfuric, and the resulting cativic acidtaken upin petroleum ether; this solution, after treatment to removewater (as by subjecting to a water-absorbing agent inert to theingredients), is then again ammoniated. The impurities will now be foundin the petroleum ether layer, and the pure solid gummy ammonium cativatemay be used as such or hydrolyzed as described above to produce cativicacid. Another method of'recovering cativic acid from ammonium cativateconsists in heating the latter, as on a water-bath,

whereby anhydrous ammonia is given off andmay be recovered for reuse,and cativic acid remains in pure form. Thisis preferably carried out ina non-oxidizing atmosphere.

In carrying out the fourth of the above-itemized neutralizationprocesses, I dissolve a cativic acid-containing material in acetone, andtreat the acetone solution with a concentrated aqueous solution ofalkali. It is evident that whether there will be neutralization only, orsaponification as well, depends upon the relative amounts of alkali, andalso upon the temperature and length of treatment. The alkali salt ofcativic acid resulting from this procedure will be in the aqueous layer,while the other organic components, such as cativyl alcohol, cativylcativate,.

cativene, etc. will be found in the acetone layer. The two layers may beseparated, and the purified cativic acid in the form of its saltssegregated from the other components. The salt may then be used as asource of pure cativic acid, in accordance with methods elsewheredescribed here- My fifth method of preparing pure cativic acid by theneutralization procedure consists in heat ing Cativo or other suitablecativic acid-containing material in a high-boiling solvent with somemetallic oxides, hydroxides, carbonates, acetates, and the like,preferably in a finely-divided state and with stirring; cativic acidthuscombines with the base, forming the corresponding salt. For instance,'70 parts of impure cativic acid is heated with 30 parts of ahigh-boiling petroleum hydrocarbon, boiling at, say, 160 C., to about-135 C. Then the calculated amount of litharge is added, preferablygradually, the water of reaction boiling 01f, and the lead cativatedissolving in the high-boiling petroleum hydrocarbon. It is advantageousto filter at this point. The lead cativate solution, containing cativyla1- cohol, cativyl cativate, or cativene, as thecase may be, is eitherevaporated to dryness, and then the impurities dissolved therefrom witha selective solvent, or the solution is diluted with such a selectivesolvent, thereby precipitating the salt of cativic acid, which issubsequently washed with a non-solvent for the salt. The impurities arerecovered from the solvents by any of the usual methods, while thecativate salt is dried, and utilized as such, or may be decomposed withor without previous drying, into cativic acid, in the manner alreadydescribed. .As usual, an inert, non-oxidizing atmosphere isadvantageously used.

In carrying out the solvent process for obtaining cativic acid, theCativo resin is first treated with aqueous alcohol containingapproximately 75% alcohol; cativic acid goes into solution but theundesirable impurities and otheringredients remain as a bottom sludge.The alcoholic-aqueous solution may be poured oil or filtered, andcativic acid maybe recovered therefrom in,several ways. For instance,the alcohol solution may be distilled or diluted until the alcoholcontent is about 50% or less, in which mixture cativic acid becomesthereby substantially insoluble, and the acid thus separated may be, ifso desired, taken up by a solvent immiscible with the 50% aqueousalcoholic solution, such as petroleum ether or other aliphatichydrocarbons, and thus separated. Cativic acid then may be recovered byevaporation of the solvent, preferably in a non-oxidizing atmosphere.Or, the 75% alcoholic solution may be shaken out with an immisciblesolvent such as certain aliphatic hydrocarbons, e. g. Varnoline,

part of cativic acid going into the hydrocarbon solution. After theseparation of the solvent, the alcoholic solutioncontaining some cativicacid may be used again for extraction of another portion of Cativoresin, and so on, and the solution freed from "the solvent if sodesired, and cativic acid then obtained. Or, the solution may be used assuch. The 75% alcoholic solution may be decolorized, or substantiallyso, if so desired, by adding sodium hydrosulphite in the amount of ofthe total weight, shaking out for a while, possibly gently heating, andpreferably filtering. Decolorization of color-imparting constituents ofcativic acid may also be accomplished bysunlight, or by sources ofsuitable artificial light which has an excellent decolorizing effectthereon, especially in solution. 7.

Cativyl alcohol is a practically colorless, viscous liquid, having aslight sweetish odor, and boiling at 209 C. at 4 mm. Representativesamples of purified cativyl alcohol show a specific gravity at 27 C. of0.9784, and a viscosity at 26 0., as determined by relative time ofoutflow from a burette, of 117.5 times that of water. Carefulexamination of cativyl alcohol shows it to be the alcohol correspondingto cativic acid, and that the molecular formula is accordingly CzoHzsO.This is advanced as the most probable formula so far as I have been ableto ascertain; the difculty of determining the exact formula of a substance having so large a molecule is readily evident, and the statementsmade hereinbefore with respect to ascertaining the formula of cativicacid apply similarly to cativyl alcohol.

Various methods for preparing cativyl alcohol have already beendescribed, in connection with the several neutralization processes forthe production of 'cativic acid.

Alternativelmcativyl alcohol may be prepared from Cativo resin, or fromcativyl cativate alone or in mixtures with other materials,-for example,the residues (chi fly cativyl cativate) obtained by the distillation orthe solvent processes described above for making cativic acid. Methodsfor this have already been pointed out herein. Thus, the cativylcativate may be saponified and the two resulting materialsseparated,-one of these being cativyl alcohol and the other the soap orsalt of cativic acid. Methods of separaticn are clear from the foregoingdisclosure.

Another method of preparing cativyl alcohol is to heat cativyl cativate(or a suitable material containing it) in a high vacuum, with a compoundhaving one or several esterifiable OH groups, the heating being carriedon at a temperature above the boiling point of cativyl alcohol.Alcoholysis takes place, the higher-boiling alcohol replacing cativylalcohol which is thus freed and may be readily removed by distillationat the proper temperature and pressure.

Cativyl alcohol may be also prepared from a material containing cativylcativate, by saponifying cativyl cativate, evaporating to dryness, andvacuum-distilling cativyl alcohol, whereby the salt of cativic acidremains behind. If the other low-boiling constituents of Cativo havebeen previously removed, according to some of the methods indicatedabove, or if they are fractionated during this procedure by distillingthem at their much lower boiling points, pure cativyl'alcohol may thusbe easily obtained. But this method is liable to furnish cativic acid ofless purity than those obtained by the other methods, due to the fact,that the cativlc salt is liable to retain some cativyl alcohol. Ofcourse, here also, as in all other operations, where some cativicproduct is subjected to elevated temperatures, the employ--. ment of aninert, non-oxidizing atmosphere is advantageous.

As far as I am aware, I am the first to prepare cativyl alcohol, or evento recognize that such a compound can be prepared. It is now possible,allowing the methods herein set forth, to prepare cativyl alcoholreadily and conveniently, and to prepare it in as pure a form as may bedesired.

While certain specific examples of this invention have been describedherein above by way or illustration, it is to be understood that thishas been done for the purpose of aifording an understanding of thisinvention and the scope of this invention is not to be limited thereby,but is to be limited only by the language of the following claims.

I claim: i

1. As a new compound, cativyl alcohol, being the alcohol correspondingto the alcohol radical oi"; the principal ester constituent of Cativoresin.

2. As a new compound, cativyl alcohol, being a practically colorless,viscous liquid, boiling at 209 C. at 4 millimeters of mercury pressure,absolute.

3. Method of preparing cativyl alcohol, com prising reacting a materialcomprising cativyl cativa'te with a metal compound having a basicreaction, said compound being of the class consisting of metal oxidesand hydroxides and salts of relatively strong metal hydroxides withrelatively weak acids, whereby to form a metal cativate and cativylalcohol.

4. Method of preparing cativyl alcohol comprising saponiiying cativylcativate, and then distilling off the cativyl alcohol produced by thesaponification.

5. Method ofpreparing cativyl alcohol comprising saponiiying cativylcativate, and then extracting by meansof a solvent the cativyl alcoholproduced by the saponification.

NICHOLAS L. KAIMAN.

